Full nitrogen recovery and potable water production from human urine by membrane distillation

Human urine offers some interesting possibilities for ammonia and potable water recovery. Membrane distillation holds possible advantages over existing urine treatment technologies, specifically regarding ammonia recovery. It was shown that up to 95 m% of all ammonia present in hydrolyzed urine could be recovered by increasing the urine pH to 10.5 or higher within a period of 2 hours, with a maximal separation factor of up to 16. The possibility of potable water production was investigated in human urine by assessing the permeate water quality, maximum recovery and mid-term process stability. It was shown that at least 75% of the available water could be recovered from non-hydrolyzed human urine without process failure. As such, membrane distillation is a viable alternative for existing urine treatment